[WIP] Add DisplayOverclock

[AAGaming00]

DisplayOverclock

This plugin allows you to overclock your Steam Deck internal display to up to 70hz using the built in but currently disabled display overclocking feature in yesterday's Steam Client Beta.

Checklist:

Developer Checklist

• [x] I am the original author or an authorized maintainer of this plugin.
• [x] I have abided by the licenses of the libraries I am utilizing, including attaching license notices where appropriate.

Plugin Checklist

• [x] I have verified that my plugin works properly on the Stable and Beta update channels of SteamOS.
  • This plugin cannot work on Stable currently, and will detect the Steam Client version and show a modal if it is too old.
• [x] I have verified my plugin is unique or alternatively provides more/alternative functionality to a similar plugin already on the store.

Plugin Backend Checklist

• No: I am using a custom backend other than Python.
• No: I am using a tool or software from a 3rd party FOSS project that does not have it's dependencies statically linked.
• No: I am using a custom binary that has all of it's dependencies statically linked.

Testing

• [ ] Tested on SteamOS Stable/Beta Update Channel.

[AAGaming00]

awesome, wait on merging this until it handles external displays correctly though